Russians delay Soyuz re-entry as Progress failure probe proceeds

Russian managers have decided to briefly postpone the planned re-entry and landing of a Soyuz ferry craft carrying three long-duration space station crew members amid work to pinpoint the cause of a malfunction in a Soyuz-U rocket Aug. 24 that destroyed an unmanned Progress cargo ship bound for the orbital lab complex.

Hurricane Katia churns in the Atlantic Ocean 240 miles below the International Space Station, framed by a Russian Progress cargo ship at upper left and the Soyuz TMA-02M crew ferry craft at lower left. (Photo: NASA)

Outgoing Expedition 28 commander Andre Borisenko, Alexander Samokutyaev and NASA flight engineer Ronald Garan will remain in orbit an additional eight days and return to Earth aboard the Soyuz TMA-21 spacecraft around 12:01 a.m. EDT (GMT-4) on Sept. 16, landing in Kazakhstan to close out a mission spanning 164 days five hours and 42 minutes since blastoff April 4.

The Russians had planned to launch three replacement crew members -- Anton Shkaplerov, Anatoly Ivanishin and NASA flight engineer Dan Burbank -- aboard the Soyuz TMA-22 spacecraft on Sept. 22. But that flight will be delayed at least a month or so, officials say, while the Soyuz failure investigation plays out. The Soyuz-FG booster used to launch manned Soyuz ferry craft uses the same third stage as the Soyuz-U that failed last week.

Russian engineers say the Soyuz-U third stage malfunction that triggered an engine shutdown five minutes and 20 seconds after liftoff apparently involved a gas generator used to drive a turbo-pump that feeds propellant to the combustion chamber. No other details were provided and it's not yet known what sort of fix might be needed.

Assuming the gas generator was, in fact, the culprit and assuming no major redesign or repair work is necessary, Russian space managers hope to press ahead with two already-planned unmanned flights to make sure the system is operating normally before launching the Soyuz TMA-22 around the end of October.

Until then, the station will be staffed by Expedition 29 commander Michael Fossum, Sergei Volkov and Satoshi Furukawa, launched June 7 aboard the Soyuz TMA-02M spacecraft. As it now stands, they would return to Earth around Nov. 17. Their replacements -- Oleg Kononenko, Don Pettit and Andre Kuipers -- would launch aboard the Soyuz TMA-03M spacecraft in early December to boost the station crew back to six.

But that assumes the Progress failure investigation proceeds smoothy and no major problems are encountered.